The inherent capability to deform and reform in a predefined environment is a unique property existing in shape memory polyurethane. The intrinsic shape memory ability of the polyurethane is due to the presence of macro domains of soft and hard segments in its bulk, which make this material a potential candidate for several applications. This review is focused on manifesting the applicability of shape memory polyurethane and its composites/blends in various domains, especially to human health such as shielding of electromagnetic interference, medical bandage development, bone tissue engineering, self-healing, implants development, etc. A coherent literature review highlighting the prospects of shape memory polyurethane in versatile applications has been presented.

Nicotinamide mononucleotide (NMN), a precursor of NAD+, can be synthesized by the conversion of nicotinamide with the help of nicotinamide phosphoribosyl transferase (NAMPT) via the salvage pathway. NMN has recently gained great attention as an excellent therapeutic option due to its long-term effective pharmacological activities. In this study, we constructed a recombinant strain of Escherichia coli by inserting NAMPT and phosphoribosyl pyrophosphate synthetase 1 (PRPS1) and PRPS2 (from Homo sapiens) genes to investigate the effect of PRPS1 and PRPS2 on NMN synthesis. The metabolically engineered strain of E. coli BL21 (DE3) exhibited 1.57 mM NMN production in the presence of Mg2+ and phosphates in batch fermentation studies. For further improvement in NMN production levels, effects of different variables were studied using a response surface methodology approach. A significant increment was achieved with a maximum of 2.31 mM NMN production when supplemented with 1% ribose, 1 mM Mg2+ and phosphate, and 0.5% nicotinamide in the presence of a lactose (1%) inducer. Additionally, insertion of the PRPS1 and PRPS2 genes in the phosphoribosyl pyrophosphate synthesis pathway and individual gene expression studies facilitated a higher NMN production at the intracellular level than the reported studies. The strain exhibited intracellular production of NMN from cheap substrates such as glucose, lactose, and nicotinamide. Hence, the overall optimized process can be further scaled up for the economical production of NMN using a recombinant strain of E. coli BL21 (DE3), which is the future perspective of the current study.

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BACKGROUNDThe present study is focused on the decomposition of hydrogen peroxide (H2O2) using magnetic iron oxide nanoparticles (Fe3O4 NPs). Intrinsic peroxidase mimicking activity of Fe3O4 NPs helps in decomposition of H2O2 for the generation of •OH radicals during the Fenton process. A response surface methodology based central composite design (CCD) method was adopted to optimize five different process parameters: reaction time, temperature, pH, Fe3O4 NP concentration and H2O2 concentration.RESULTSCCD‐predicted H2O2 decomposition (%) showed close agreement with the experimental results, confirming the good fit of the experimental data to the model. A maximum H2O2 decomposition of 92.31% was achieved with an initial H2O2 concentration of 31.07 mg L−1, Fe3O4 NPs of 1.34 wt%, pH of 5.29, temperature of 23.1 °C and reaction time of 5.6 min as optimal values. The morphology and structure of Fe3O4 NPs before and after the reaction process were characterized using scanning electron microscopy, energy‐dispersive X–ray spectroscopy, Fourier transform infrared spectroscopy, X‐ray diffraction spectroscopy and thermogravimetric analysis.CONCLUSIONThe characterization data showed no significant changes in the structure of Fe3O4 NPs after the reaction compared to the pristine Fe3O4 NPs. The catalytic efficiency of these NPs was found to be in close agreement with other similar materials reported in previous literature. These optimization variables for H2O2 decomposition using Fe3O4 NPs may be useful in designing protocols for practical application at a large scale. © 2020 Society of Chemical Industry

Renewable energy resources are considered to be promising for the development of a sustainable circular economy. Among various alternatives, the microbial route for various biofuels production is quite lucrative. Use of cellulose and lignocellulose for methane, H 2 , organic acids, ethanol, and cellulase has been explored a lot in the past few decades. The major leftover or a coproduct of these processes belongs to lignin-an aromatic cross-link polymer and one of the most abundant complex compounds on earth. A successful bioconversion route of lignin into high-value products is highly desirable for biorefinery perspective. It requires a complex set of enzymes/catalysts to decompose lignin through depolymerization and oxygen removal leading to its monomers that can be metabolized by engineered organisms to synthesize muconic acids, polyhydroxyalkanoates (PHAs), methane, and other high-value products. This article will focus on the opportunities and challenges in the bioconversion of lignin and its derivatives into PHAs.